The validity of sex ed programs advocating contraceptive use has been demonstrated in the US. There's extensive literature, here's a recent one, you can check their references too: John S Santelli, Laura Duberstein Lindberg, Lawrence B Finer, Susheela Singh, "Explaining recent declines in adolescent pregnancy in the United States: the contribution of abstinence and improved contraceptive use", American journal of public health, 2007 vol. 97 pp. 150-6